Protracting level



Nov. 26, 1957 J. HOPKINSON, JR 2,814,128

PROTRACTING LEVEL Filed April 9, 1957 ATTORNEY):

PROTRACTING LEVEL Joseph Hopkinson, Jr., Sicklerville, NTJ.

Application April 9, 1957, Serial No. 651,724 10 Claims. c1. 33-213 This invention relates generally to measuring devices, and is especially concerned with a novel protracting level for ascertaining and delineating angles and/or rise per unit length.

' While there are in the prior art devices of similar purpose, these devices have not found general acceptance for numerous reasons. In particular, previous devices of the instant type have been relatively complex and expensive in their construction, unduly difiicult "and tedious to operate, and have been limited in their versatility and accuracy;

It is therefore a general object of the present invention to provide a measuring instrument for ascertaining or delineating angles or rise which overcomes the abovementioned difi'iculties, is capable of being quickly and easily set and read'to a high degree of accuracy, which is extremely simple and inexpensive in construction, and is durable and troublerfree in use.

It is a more particular object of the present invention to provide a measuring instrument having the advantageous characteristics set forth in the preceding paragraph which is adapted to be adjusted and readfrom opposite sides for maximum convenience, the different sides being capable of bearing graduations in different units for versatility in use, and which requires a minimum of simple and easily assembled partsso as to be adapted for manufacture and sale at reasonable cost.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

In the drawings:

Figure 1 is an elevational view showing one face of a measuring device constructed in accordance with the present invention; 7

Figure 2 is a sectional elevational view taken substantially along the line 22 of Figure 1;

Figure 3 is a sectional view taken substantially along the line 3--3 of Figure 2; and

Figure 4 is a partial elevational view showing an ,opposite face of the device of Figure 1.

Referring now more particularly to the drawings, the embodiment of the invention illustrated therein comprises a housing, generally designated 10 which includes a pair of opposed, parallel spaced walls 11 and 12, and an intermediate cylindrical wall 13 interposed between the first-mentioned opposed walls.

More specifically, the opposed walls 11 and 12v may each be formed of a generally rectangular flat, plate, preferably having its edge surfaces normal to its faces. The wall or plate 11 is provided with a generally centrally located, substantially circular through opening- 15, and is further formed with a retaining lip 16 extending nited States Patent "ice 2 lcircumferentially about the opening 15 and projecting into the opening, substantially flush with the outer surface of the plate 11. Thus, the retaining member or lip 16 defines an annular shoulder 17 extending about the opening 15 and facing toward the interior of the housing 10.

Similarly, the wall plate 12 is centrally formed with a substantially circular through opening 20, and is provided with a retaining member or lip 21 extending cir cumferentially about the opening and projecting into the latter, substantially flush with the outer face of the plate. Also, the lip 21 defines an inwardly facing shoulder 22 extending about the opening 20 of plate 12. With the wall plates 11 and 12 arranged in their parallel spaced, opposed relation, the openings 15 and 20 are in sub? stantial alignment with each other. 7 i The peripheral housing wall 13 is of generally cylindrical configuration and arranged in substantial axial alignment with the wall openings 15 and 20 having its end edges in abutting engagement with the inner faces of respective plates 11 and 12. The inner faces of the plates 11 and 12 may be provided with annular locating ribs 25 and 26, respectively, or other suitable means engageable with end edges of the peripheral wall 13 to properly locate the latter between the platesrand, fasteners 27 may extend between the plates 11 and 12 being secured to adjacent corners thereof, to retain the plates and intermediate wall 13 in their assembled relation. While the plates 11 and 12 are illustrated as of rectangular configuration, and their respective openings 15 and 20 of generally circular configuration, so that all edge surfaces of the plates are disposed normal to radii or diameters of the plate openings, it is only necessary that one external surface of the housing 10 be normal to a pair of aligned diameters of the openings 15 and 20. For example, the plate edges 29 and 30 of plates 11 and 12, respectively, may be considered as defining an external surface of the housing 10 extending between the outer faces of housing walls 11 and 12 in a plane normal to aligned diameters of the wall openings 15 and 20. a i

Further, as seen in Figure 1, the external surface of housing wall 11 is provided with markings extending about the opening 15, which markings designate angles in the manner of a protractor and commence at adiam- 'eter designated 0," which diameter is normal tothe housing surface 29, 30, being generally vertical in the drawing. On the external face of the housing wall 12, extending about the wall opening 20, are markings or graduations indicating rise or pitch per unit length. These markings also commence at a diameter designated 0 extending generally normal to the external housing surface 29, 30, being vertical in the drawing and in alignment with the vertical diameter of the angle markings of wall 11. I

Rotatably received in the circular opening 15 of wall plate 11 is an annular member or ring 33 having a central window or opening 34 preferably closed by a transparent window or plate 35. The annulus 33 is peripherally cut-away, as at 36 to receive the retaining lip 16 and define a peripheral, outwardly facing annular shoulder 37 engageable with the inwardly facing lip shoulder 17. Further, the annulus 33 may be formed to project outward beyond the outer face of plate 11, as at 38, and shaped to define a frusto-conical, or annular beveled marginal surface 39 contiguous to the outer surface of plate 11.

Projecting rigidly inward, into the housing 10, from the lower region of annulus 33 as seen in Figures 2 and 3, is a plate or ledge 41, which extends chordally across the inner side of the annulus and is reinforced on its underside by pins 42. The ledge or plate 41 has its Patented 0v. 26, 1957 mid-region approximately tangent to the central annulus opening 34. Spaced above one end of the plate 41, a relatively thick abutment member 43 projects inward from the annulus 33, adjacent to and on one side of the annulus opening 34. Spaced above the left-hand end of the ledge 41, as seen in Figure 3, and approximately diametrically opposite to the relatively thick abutment 43, is a relatively thin abutment member or plate 44 which also pnojects rigidly inward from the annulus 33. A spirit level 45 extends chordally across the opening 34 of annulus 33, and is held by and cemented in position between the ledge 41 and abutments 43 and 44. Thus, the spirit level 45 is rotatable with the annulus 33.

On the outer marginal surface 39 of the annulus 33 are provided markings, as seen in Figure 1, which define a vernier scale for use in cooperation with the scale markings on the outer face of the housing wall 11. The marking of the vernier scale is on a diameter of the annulus 33 normal to and passing through the mid-point of the level 45. On the inner side of the annulus 33, at circumferentially spaced locations thereon, may be provided locating beads 47, for a purpose appearing presently.

. Rotatably received in the circular opening 20 of wall plate 11 is an annular member or ring 50, which may be of substantially the same construction as the annular member 33. More specifically, the annulus 50 includes a central opening 51, and is peripherally cut away at 52 to receive the retaining lip 21 and define an outwardly facing shoulder 53 engageable with the inwardly facing lip shoulder 22. A transparent plate or window 54 is preferably secured in position extending across the opening 51, and an annular ridge 55 projects outward from the annulus 50, beyond the outer surface of plate 12, and is formed with a frusto-conical or beveled marginal surface .56 contiguous to the outer plate surface. A chordally disposed ledge 58 projects rigidly inward from the inner side of annulus 50, substantially tangent to the annulus opening 51, and is reinforced on its radially outward side by rigid pins 59. Fixedly secured to and projecting rigidly inward from the inner side of annulus 50, at approximately diametrically opposed points thereof, and approximately equally spaced from opposite ends of the ledge 58 are a relatively thin, plate-like abutment member 60, and a relatively thick abutment member 61. The members 60. and 61 correspond respectively to the members 44 and 43 of annulus 33. Further, the abutment members 43 and 58 of the annuli 33 and 50, respectively, project inward in offset relation into overlapping engagement with each other, as best seen in Figure 2, while the abut ment members 44 and 61 of the respective annuli also project inward in offset relation into overlapping engagement, see Figure 3. Thus, the annuli 33 and 50 may be identical in construction, and are arranged in the housing in facing relation with each other, one being inverted relative to the other. As the overlapping abutment members of the annuli each terminate short of the otherannulus, it will be understood that the annuli are movable inward into the housing 10 toward each other, from their illustrated position. However, the overlapping engagement of the abutment members of one annulus with the abutment members of the other annulus serve to drive or effect rotation of either annulus upon rotation of the other annulus.

A spirit level 63 extends chordally across the inner side of annulus 50, being fixedly secured, as by cement or the like, between the ledge plate 58 and abutment members 60 and 61, in the same manner as the level 45. At circumferentially spaced locations on the inner side of the annulus 50 may be provided locating lugs or beads 64, corresponding to the beads or lugs 47 of the annulus 33. The external surface 56 of the annulus 50 is preferably provided with markings, see Figure 4, which cooperate with and define a Vernier scale for the scale marked on the external surface of plate 12. The 0 marking of the Vernier scale is on a diameter of the annulus 50 normal to and passing through the mid-point of the level 63.

In order to yieldably retain the annuli 33 and 50 in their illustrated spaced apart relation, suitable resilient means, such as a coil compression spring 66 is arranged axially within the housing 10, being interposed between and having its opposite ends in bearing engagement with the inner sides of the respective annuli. Thus, the spring 66 serves to resiliently and yieldably urge the annuli outward with their outwardly facing shoulders 37 and 53 in frictional bearing engagement with the inwardly facing shoulders 17 and 22, respectively. The beads 47 and 64 aid in retaining the coil spring properly located relative to the annuli.

While the operation is believe-d to be apparent from the above-detailed description, a brief summary of the operat ing procedure follows. If it be desired to measure the angle of inclination of a member, say the rafter of a building, .the housing 10 may be arranged with its surface 29, 30 seatedon the upper side of the rafter, and the annulus 33 rotated to center the bubble in the level 45. More specifically, the annulus 33 may be manually depressed inward into the housing 10, thereby releasing the shoulders 17 and 37 from their frictional engagement, and facilitating rotation of thetannulus. Of course, the annulus 50 rotates with the annulus 33, and while imparting some resistance to rotation, such resistance is not substantial. With the level 45 properly positioned, the angle of inclination may be read on the graduated scale of plate 11 by. the vernier scale of the marginal annulus portion. Also, the rise per unit of length may be read on the scale of plate 12 by the Vernier of annulus 50. The procedure may, of course, be reversed, according to the desired in- .spirit of the invention and scope of the appended claims.

For example, it is intended to be comprehended herein that one of the annular members may be eliminated, and

that its receiving wall opening merely be closed.

What is claimed is:

l. A measuring device comprising a hollow housing having a generally circular opening in one wall, said housing having one external surface disposed generally normal to a diameter of said opening, said one wall being provided with external markings about said opening commencing at said one diameter, an annulus rotatably received in said opening and provided on its external surface with marginal markings adjacent to and adapted to cooperate with said first-named markings, a spirit level carried in said annulus in predetermined relation with said marginal markings, resilient means interiorly of said housing in bearing engagement with said annulus and yieldably urging said annulus outward through said opening, and retaining means on said one housing wall engageable with said annulus to hold the latter in said opening against the force of said resilient means and frictionally retain said annulus in any selected position of its rotative movement, whereby said annulus is adapted to be rotated to center the bubble in said spirit level when said one housing surface is at a desired inclination with said first and second named markings cooperating to indicate said inclina-tion.

2. A measuring device according to claim 1, said resilient means comprising a coil compression spring having one end in bearing engagement with said annulus.

3. A measuring device according to claim 1, said retaining means comprising a lip on said one housing wall projecting into said opening for said holding engagement with said annulus.

4. A measuring device according to claim 1, wherein said marginal markings define a Vernier scale for said first-named markings.

5. A measuring device according to claim 1, wherein said first-named markings indicate angle of inclination of said one housing surface.

6. A measuring device according to claim 1, wherein said first-named markings indicate rise per unit length of the inclination of said one housing surface.

7. A measuring device comprising a hollow housing having a pair of spaced opposed walls formed with generally circular aligned openings, said housing having an external surface extending between said pair of opposed walls generally normal to aligned diameters of said openings, each of said opposed walls being provided with external markings about its respective opening commencing at the associate one of said diameters, a pair of spaced aligned annuli respectively rotatably received in said openings and each provided on its external surface with marginal markings adapted to coperate with said first-named markings of the adjacent housing wall, a spirit level carried in each of said annuli in predetermined relation with the marginal markings thereof, resilient means in said housing interposed between and in bearing engagement with said annuli to yieldably urge the latter outward through their respective openings, retaining means on each of said opposed walls engageable with the adjacent wall of said annuli to retain the latter in its opening and frictionally hold the retained annulus in any selected position of its rotative movement, said annuli thus being resiliently yieldable inward against the force of said resilient means away from said retaining means to facilitate rotation of said annuli, and abutment members projecting inward from said annuli into overlapping relation with each other, said abutment members being engageable with each other upon rotation of one of said annuli to efiect simultaneous rotation of the other of said annuli and being movable inward relative to each other to permit independent yieldable inward movement of said annuli.

8. A measuring device according to claim 7, said retaining means comprising a lip on each of said opposed housing walls projecting into and extending circumferentially about the respective opening for holding engagement with the adjacent annulus, and said resilient means comprising a coil compression spring interposed between and having its opposite ends in respective engagement with said annuli.

9. A measuring device according to claim 7, wherein the marginal markings of each annulus define a vernier scale for the adjacent housing wall markings.

10. A measuring device according to claim 7, wherein the markings on one of said housing Walls indicate angle of inclination of said one housing surface, and the markings on the other of said housing walls indicate rise per unit length of the inclination of said one housing surface.

No references cited. 

